133 — Interference Check and QA Findings¶

Once every panel is attached to the site and stood up on its wall line, the next question is whether they all fit. Two panels that overlap along a wall, a corner where neither panel runs through, a panel that is too long for its bay: each one is a field problem you would rather find on the drawing than at the slab.

Interference Check runs AutoCAD’s interference test on every stood-up panel and lists each clash with its cause. QA Findings opens that list again later, from the drawing, so you can work through it one finding at a time.

Where it is¶

Both buttons are on the ConstructiVision Site & Tools toolbar, next to each other:

Button	Tooltip	Typed command
Interference Check	“Run INTERFERE on the constructed panels and list every clash with its cause; the clashes are left on layer CV-INTERFERE”	`CV-INTERFERE`
QA Findings	“List the last Interference Check’s findings from this drawing; pick one to center the drawing on it”	`CV-QA`

Open a site drawing. The check works on the panels standing on the site, so attach them and tilt them up first. On a site where that has not been done, it stops at once and says so:

[CV-INTERFERE] found 0 panel xref(s) with a 3D solid -- nothing to check. Attach and Tilt-Up the panels first.

So the order is: Site Plan opens Site Options → Attach Panels → Tilt-up Panels → Interference Check. Lesson 11 covers Attach and Tilt-up.

Try it on the PDX248 site¶

The run below used the PDX248 site and its 76 panels, PDX001 to PDX076.

Before the check: stand the panels up¶

Open the site drawing and click Site Plan. Site Options opens.
Click Attach Panels. All 76 panels are placed in the site drawing, lying flat, with 76 panel marks.
Click Site Plan again, then Tilt-up Panels. All 76 panels stand up on their wall lines.

On the 76-panel site, Attach took a little over two minutes and Tilt-up about 15 seconds.

1 Interference Check¶

Click Interference Check (or type CV-INTERFERE).

Watch the command line. It reports the panels it is checking, then AutoCAD’s own count:

[CV-INTERFERE] checking 76 constructed panels ...
Comparing 76 objects with each other.
Interfering objects  (first set): 20
                    (second set): 0
Interfering pairs: 13

ConstructiVision then prints its summary and one numbered row per finding:

[CV-INTERFERE] 76 constructed panels checked: 13 interfering pair(s) between panels,
6 wall-line / corner finding(s) from 10 wall lines, 7 corners, 3 T-joints examined;
every one is a red solid on layer CV-INTERFERE.

The ConstructiVision – Interference Check window opens. On the 76-panel site it appeared about 30 seconds after the command started.
Wait for the list to fill. The first time the window opens after a check, the list can stay empty, with a busy cursor, for 10 to 30 seconds. Clicks in that time do nothing. When the summary line appears at the top, the window is ready.
The filled window shows:
- the summary at the top: 76 constructed panels, 13 interfering pair(s) between panels, 6 wall-line / corner findings from 10 wall lines, 7 corners, 3 T-joints examined;
- the 19 findings, numbered 1 to 19;
- below the list, the full text of the selected finding and its position;
- Run check again, the hint Pick a finding to center the drawing on it., and Close.
Click finding 1. The window closes, the drawing slides so that finding 1 is at the center of the screen, and the window opens again with finding 1 still selected. The zoom does not change; only the view moves.
Click Close, or press Esc, when you are done.

2 QA Findings¶

QA Findings opens the same window without running the check. Its tooltip gives its job: list the last Interference Check’s findings from this drawing, and center the drawing on the one you pick.

Click QA Findings (or type CV-QA).
The ConstructiVision – Interference Check window opens, with the same layout as above: summary line, list, Run check again, the hint, and Close.

On a drawing where no check has ever been run, the list is empty and the summary line reads:

No Interference Check has been run in this drawing – press Run check.

That is what it shows on the Arlington Airport A site drawing, AAAsite1, before any check. Click Close.

Reading the result¶

Each row names a kind, the panels involved, and the cause in plain numbers. The PDX248 run produced five kinds:

Kind	What it means	Example from the run
IN-LINE	Two panels on the same wall overlap along it.	`PDX001 / PDX002 7.63 along the wall; PDX002 is 0.75 too long for bay 2>3 (needs 396.000 = width 395.250 + edge offsets 0.375 + 0.375; bay 395.250)`
OVERHANG	At a corner, one panel runs past the far face of the other wall.	`PDX031 at PDX032 PDX031 runs 9.00 past the far face of PDX032's wall`
SHORT	A panel that should run through a corner stops short of it.	`PDX017 at PDX018 PDX017 (bypass) stops 1.38 short of the far face of PDX018's wall`
CORNER	An open corner: neither panel runs through.	`PDX015 / PDX014 open corner: neither panel runs through (PDX015 ends 7.25 short of the far face, PDX014 7.25)`
JUNCTION	Where two walls meet, the depth of the overlap.	`PDX013 / PDX014 where two walls meet: 7.25 in overlap across a 7.25 in wall`

Row 1 is the one to read closely. It does the arithmetic for you: the bay is 395.250, and the panel needs 396.000 (its width plus an edge offset at each end), so it is 0.75 too long.

When more than two panels meet at one spot, the row names all of them, and repeated overlaps at that spot are counted:

16  JUNCTION  PDX055 / PDX057 / PDX058   where two walls meet: 0.75 in overlap across a 7.25 in wall;
    ... -- overlap 1 of 2 where these panels meet, centre (5293.63 -2637.13 207.00)
17  JUNCTION  PDX055 / PDX057 / PDX058   ... -- overlap 2 of 2 where these panels meet, centre (5293.63 -2637.13 207.03)

In the drawing. Every clash is left as a red solid on the layer CV-INTERFERE. On the PDX248 run that layer held 32 objects.

Running it again. The check clears its previous results before it writes new ones. Running it a second time on the same site gave the same summary and the same 19 rows, and the drawing still held 19 findings and 32 objects on CV-INTERFERE, not double. So you can fix panels and re-run until the list comes back clean.

Picking a finding. Selecting row 1 moved the view center to row 1’s point, at 528.81, -3.63, 207.00, and left the zoom level exactly as it was.

What this lesson does not cover¶

The blank first open. After a check, the window can open empty with a busy cursor for 10 to 30 seconds before the list fills. Wait for it; clicks in that time are ignored. This is a known open defect (CV-3316).
Fixing what it finds. This lesson shows how to read the list, not how to correct each kind of finding. Correct the panel or the wall line the row names, then run the check again.
Run check again. The button is in the window, but this lesson’s run started each check from the CV-INTERFERE command instead.

Watch the lesson¶

A companion video for this lesson is planned alongside the written curriculum.